1. Technical Field
The present invention relates to storage devices in general, and in particular to an external storage device a computer network.
2. Description of the Related Art
Hard disks are often used to store data processed by a computer system. Generally speaking, a hard disk has a relatively low cost per bit and a relatively high storage capacity. However, since a hard disk relies upon mechanical actions such as rotation of a disk or movement of a magnetic head for reading and writing data, the access speed of the hard disk is much slower than a solid state storage device that is capable of reading and writing data electrically.
A semiconductor disk device is capable of compressing and writing data. However, since the efficiency of data compression depends on the contents of data being compressed, it is very difficult to provide the semiconductor disk device as an external storage device with a specific storage capacity larger than a semiconductor memory included therein.
Consequently, it would be desirable to provide an improved external storage device that is capable of storing data efficiently in a cost-effective manner.